World’s Plants Get First Checkup

Imagine seeing this personal ad in your local paper: Rare yet convivial Namibian snapdragon, fond of rocky pools and extreme growing conditions, seeks appreciative patron for monetary support and continued existence.

Chamaegigas intrepidus and tens of thousands of other endangered plants can’t speak for themselves, so some of the world’s leading botanical research institutions are speaking for them. More than a fifth of the world’s plant species are now vulnerable to extinction, according to a recent study by the Royal Botanic Gardens, Kew, in collaboration with London’s Natural History Museum and the International Union for the Conservation of Nature. 2010 is International Year of Biodiversity, the year when the world was supposed to begin slowing biodiversity decline, according to the 2002 Convention on Biological Diversity. So how are we doing? It’s difficult to say because no one is sure how many species are at risk. You can’t draw a road map without a starting point, and the Kew Gardens study aims to generate that starting point.

With over 380,000 plant species in the world, not all could be assessed. The scientists chose about 4,000 well-described target species. Kew Gardens and their partners provided information about particular species’ locations through time — data that was combined with satellite imaging and current knowledge. The sample plants were assessed by comparison with the IUCN’s Red List Index, a standardized description of the categories and criteria used to determine a species’ threat level.

They’ve also used this wealth of information to generate a fabulous accompanying website. If you’re wondering what sort of plants they studied, or want to see a world map of plant threat levels, there’s a page for that.

The numbers would disappoint anyone hoping to see an uptick in plant biodiversity. Four percent of plants were classified as critically endangered, while 22 percent were at least vulnerable. Researchers were also able, for the first time, to determine which types of plants were most threatened. Gymnosperms (meaning “naked seed,” a group that includes conifers) fared the worst, with 36 percent threatened.

In addition to identifying threatened plants, the study helped ascertain which habitats are at risk. Tropical rainforests are most threatened. Not surprisingly, humanity poses the greatest threat to plant biodiversity. But there is hope. The Kew Gardens website describes the study’s findings in detail, as well as ongoing efforts to help save plants. I recommend moseying over, and taking one small step for plantkind by helping Kew Gardens make a stand against biodiversity loss: adopt a seed.